Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety and closed-domain profile is covered. The description adds the accepted input language and the follow-up workflow, but says nothing about result count limits, ranking, or pagination behavior.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Three tight sentences, each doing work: scope and return shape, input format, next step, and the routing rule to search_hub. Nothing is redundant or buried.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With a single fully-documented parameter, an output schema, and appropriate read-only annotations, the description covers everything needed to select and call the tool correctly, including the downstream fetch step and the sibling it defers to.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100% and the parameter is already described as a natural-language query, so the baseline is 3. The description adds that the query may be Chinese or English, which is genuinely useful input-formation guidance the schema does not carry.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb (Search) and resource (the user's personal Sensefold library) and names the result shape {id, title, url, text}. It explicitly distinguishes itself from the sibling search_hub, so an agent can route without opening either schema.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Gives explicit when-to-use (one natural-language query string), when-not-to-use (tag, date, or provenance filters belong to search_hub), and the follow-up step (fetch on a result id). All the routing an agent needs is present.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.